The S&P 500 slid 0.4% to 1,685.83 at 3:01 p.m. in New York, after earlier climbing to within 2 points of 1,700. The index is poised for its first back-to-back decline in a month. The Dow Jones Industrial Average lost 37.48 points, or 0.2%, to 15,530.26, retreating from a record close yesterday. Trading in S&P 500 stocks was 9.2% higher the 30-day average during this time of day.

“The earnings are validating and supporting the market as opposed to pushing the market higher,” Mark Freeman, who oversees about $15.8 billion as chief investment officer at Westwood Holdings Group Inc. in Dallas, said by telephone. “It just speaks to how far we have come and the amount of positive expectations that have already been cleared by the market.”

The S&P 500 declined yesterday as investors weighed earnings amid speculation on when the Federal Reserve may scale back its asset purchases. Support from central banks and better- than-estimated corporate earnings have driven the S&P 500 up as much as 151% from its March 2009 low.

Economic Data

The rally has pushed valuations close to the highest level since May 2010, with the S&P 500 trading at 16.3 times reported earnings, data compiled by Bloomberg show.

When the benchmark index rose to a record close on July 22, the gauge had gained for 12 of the previous 13 trading days, a stretch that hasn’t happened since September 1995, data compiled by Bloomberg show. The 14-day relative-strength index for 83 S&P 500 stocks exceeded 70 that day, the most since May 21, Bloomberg data show. RSI measures the degree to which gains and losses outpace each other and some analysts who watch charts to predict market moves consider a reading over 70 as the stock has risen too far too fast.

“The market has had a big run and we are a bit overbought here,” Bruce Bittles, chief investment strategist at RW Baird & Co., said in a telephone interview from Sarasota, Florida. His firm oversees $100 billion. “There is a lot of optimism coming into the market short-term, so I wouldn’t be surprised if we rested in here for a while.”